Lewy body disease is a serious brain condition that can affect memory, thinking, movement, sleep, and behavior.
It is less widely known than Alzheimer’s disease, but it is one of the most common causes of dementia and is closely connected with Parkinson’s disease.
The condition gets its name from Lewy bodies, which are unusual clumps of protein that collect inside brain cells. These clumps mainly contain a protein called alpha-synuclein, which normally exists in the brain but can change shape and stick together.
As the abnormal protein builds up, brain cells may become damaged and eventually stop working properly. Depending on which parts of the brain are affected first, people can develop very different early symptoms.
Some people first have movement problems such as stiffness, shaking, slower movement, or difficulty with balance and may be diagnosed with Parkinson’s disease. Others first develop changes in memory, attention, or thinking and may receive a diagnosis of dementia with Lewy bodies.
Although these conditions can look different at first, they share the same underlying buildup of abnormal alpha-synuclein. This has made scientists increasingly interested in finding the disease before major brain damage and obvious symptoms appear.
Until recently, confirming Lewy body disease was extremely difficult while a person was alive. A definite diagnosis traditionally depended on examining brain tissue after death, while doctors caring for living patients had to rely mainly on symptoms, medical history, scans, and other tests.
Researchers at Lund University in Sweden have now reported evidence that the disease can be detected before a person develops clear symptoms. The research was published in the journal Nature Medicine and could help scientists identify people at a much earlier stage of the disease.
The researchers used a test that looks for abnormal alpha-synuclein in cerebrospinal fluid. This clear liquid surrounds the brain and spinal cord and can contain biological signs of changes taking place inside the nervous system.
The study included more than 1,100 people who were considered healthy and did not have clear problems with thinking or movement when they entered the research. The scientists found that about one in 10 already had evidence of abnormal alpha-synuclein in their cerebrospinal fluid.
This finding suggests that Lewy body disease can begin quietly years before it becomes noticeable in everyday life. During follow-up, people with these early biological signs were more likely to develop changes in thinking or movement, and some later developed Parkinson’s disease or dementia with Lewy bodies.
The researchers also found an important connection with the sense of smell. People with early signs of Lewy body disease were more likely to have a reduced ability to identify smells, even when they had not noticed the change themselves.
Loss of smell is already known to occur years before movement problems in some people with Parkinson’s disease. Because smell testing is simple and inexpensive, the researchers suggest it could eventually help identify older adults who may benefit from more detailed testing.
For example, a smell test might be used as an initial screening tool for people over a certain age. Those with poor results could then be considered for a cerebrospinal fluid test, although more research is needed before such screening becomes part of routine health care.
Finding the disease early could become especially valuable as researchers develop treatments designed to slow or stop the harmful protein buildup. Treatments for brain diseases often have the best chance of helping when they are started before large numbers of brain cells have been damaged.
The study also showed that some people had biological signs linked to both Lewy body disease and Alzheimer’s disease. These people tended to decline more quickly, suggesting that having more than one disease process in the brain may lead to faster worsening.
Researchers hope that future tests will become even easier. A blood test would be more convenient than collecting cerebrospinal fluid, but detecting the relevant protein changes in blood remains difficult and will require further scientific work.
The new findings do not mean that everyone with a poor sense of smell has Lewy body disease, and the test is not yet a general screening test for healthy people. Still, the research offers a clearer picture of how early the disease may begin and could help future clinical trials test treatments before serious symptoms develop.
Earlier detection could eventually give doctors and families more time to plan care and could allow new treatments to be used at the stage when they may have the greatest effect. For a disease that can develop silently for years, finding that hidden period may be an important step toward better prevention and treatment.
If you care about brain health, please read studies that eating apples and tea could keep dementia at bay, and Olive oil: a daily dose for better brain health.
For more health information, please see recent studies what you eat together may affect your dementia risk, and time-restricted eating: a simple way to fight aging and cancer.
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